I'm talking about the ECT engine coolant temperature sensor....
He removed his sensor and it was covered in a layer of black crud... He sanded it off and that fixed his car.
His ECU was getting false or at least inaccurate data.
Sorry, I quickly scanned your post, and thought I saw EGR, probably because I see a lot of posts on the forum about the EGR issue, and I assumed that is what it was.
As for the ECT, I will check it out. I did consider this, as I had a problem on another car of mine, with some similar symptoms, that ended up being ECT sensor.
One day, my Turbo MR2 has stalling issues, CEL (I think it was code 22), and hard start after warm up. As soon as it cooled, it started fine.
It ended up being the ECT sensor, as the CEL code said. Easy and cheap fix.
I am not sure this is the issue on the P5, as not all the symptoms don't match up. One example, I had stalling issues when the motor was cold. Although, other than what I suspect was ECU reset issues, I haven't really had any stalling problems since I replaced my fuel filter and pump.
Anyways, thanks for the advice from you and everyone else. I really need to take it for a drive on a cold day, but I just haven't been able to yet. Hopefully I will soon.